The present invention generally relates to an home network architecture, and more specifically, to an home network architecture that is capable of handling analog and digital signals in a more efficient manner.
A traditional cable network is shown in FIG. 1. As shown in FIG. 1, a cable head end provides signals to a number of residences equipped to receive and consume such signals. Each residence may have one or more pieces of equipment that are configured to receive signals from the cable head end, including for example, an analog television, a cable phone, a cable modem, a cable set-top box and other cable devices, etc.
In a traditional cable network, both analog and digital signals can be transmitted. Typically, bandwidth delivered by the cable network is up to 860 MHz. Very often, lower frequency band below 52 MHz is utilized for digital upstream link; upper frequency band (from 52 MHz to 860 MHz) is utilized for downstream content delivery and is divided based on the nature of the signals, more specifically, analog and digital. Generally, a cable plant today has up to 80 analog channels, which occupies up to 480 MHz of total band, leaving about as low as 320 MHz band for all the digital services.
Analog channels typically occupy the frequency band beginning at 55 MHz. For example, the traditional analog television channels 2, 3 and 4 occupy the frequency band at 55 MHz, 61 MHz and 67 MHz respectively. As a result, upstream frequency is limited to 52 MHz. In order to provide users with additional upstream bandwidth, a node split is required where fewer users can share the same 52 MHz bandwidth. FIG. 2 is a diagram illustrating the upstream frequency plan of a conventional cable plant.
The use of analog channels is relatively inefficient. Each RF (radio frequency) channel is configured to accommodate one analog program. On the other hand, multiple (e.g., ten) digital programs can be accommodated by each RF channel. Therefore, with the constantly increasing demand for bandwidth, use of RF channels for analog programs has become wasteful and inefficient.
Furthermore, in a traditional cable network that provides digital signals, a specialized digital set top box is needed for each device that is to receive the digital signals. For example, if there are three televisions in the residence and if each of the televisions is to receive the digital signals, then three digital set top boxes would be needed. Since each digital set top box is quite expensive, the relatively high cost has impeded the growth and popularity of digital cable subscriptions. Moreover, those digital set top boxes very often are not compatible with the functions of existing analog devices. For example, the pre-set recording function of a current analog video cassette recorder does not work with any existing digital set top box.
In addition, due to certain practical constraints, subscribers to traditional analog cable networks and digital cable networks are offered different types of services. Subscribers to digital cable networks are often offered premium services, such as, premium channels and pay-per-view programs, etc. Such premium services are usually not offered to subscribers to analog cable networks.
Hence, it would be desirable to provide an home network architecture that is capable of providing analog and digital signals in a more efficient manner.